In article ulKDc.882796$Pk3.372337@pd7tw1no, Tony Hwang wrote:
Jake wrote:

The original question was about efficiency and not safety. UL ratings
in the US rate an appliance at X watts for the absolute possible worst
case scenario. Pf, service inductance, and other factors are used for
when you're trying to squeeze the most out of your energy dollar, or
engineering new equipment. When that nameplate goes on any appliance
that's UL listed, rest assured the current ratings displayed there are
the absolute highest that piece can possibly consume.

Hi,
I don't think so. Look at a motor for an example. Does it show start
surge current? You said absolute highest.

I'm sure he meant the highest current sustained long enough to affect
the ultimate temperature of the wires that have to carry that current.
If a motor draws 10 amps continuously, any 12 gauge wire carrying that
current will not get any hotter (but will aproach whatever the final
temperature is very slightly more quickly) if that motor draws 100 amps
for 1/4 second while starting than if it's current consumption does not
exceed 10 amps when starting.

Incandescent lightbulbs often draw, usually for no more than a few
milliseconds, a peak current 10-15 times their steady-state current when
they start.

- Don Klipstein )